common name for social insects of the family Formicidae, in the order Hymenoptera (q.v.) , which also includes the bees and the wasps. Unlike bees and wasps, some species of which are solitary, all ants are social, living in organized colonies. True ants are to be distinguished from the so-called white ants, or termites, constituting the separate order Isoptera.
In most ant species, males remain winged throughout life, and females are winged until after mating. Certain wingless females, called workers, are usually infertile. The fertilized female becomes the queen of the colony, with the main function of laying eggs. The males die after mating, and the workers gather food, care for the young, and defend the colony. The nests of many species of ants commonly consist of chambers and galleries excavated under stones or logs or underground; some species construct their nests in mounds of earth and vegetable matter or in decayed trees.
The ant family contains more than 4500 described species, widely distributed in temperate and tropical countries. The ant body consists of head, thorax, and abdomen, with the abdomen articulated to the thorax by means of an abdominal pedicel, or stalk.
The four life stages of an ant are egg, larva, pupa, and adult. The minute white or yellowish eggs laid by the queen hatch in two to six weeks and develop into white larvae, or grubs. After feeding a few weeks to several months larvae become pupae, commonly but incorrectly called ant eggs. In some species the pupae are naked, and in others they are covered with cocoons spun from a substance that they secrete at the end of the larval stage. After the pupal stage, during which no food is taken, the adults appear. During development the immature ants are fed, cleaned, and attended by the adult workers. As in all insects with a complete metamorphosis, the ant has attained its full size when it leaves the pupa stage. Left to themselves, males generally die after fertilizing the queens in the nuptial flight, and queens and workers may live for several years. Queens of some species of the genus Formica are known to live longer than 15 years.
Ants are generally omnivorous; some species, however, eat only certain
specialized foods. Most ants build some sort of nest and store food there. A few
species have developed highly specialized agricultural or pastoral habits.
Pogonomyrmex barbatus of the central U.S. and Mexico frequents fields of grass,
harvesting and storing the grass seeds. Some species of the widely distributed
harvester ants, which gather grain for food, have developed specialized workers,
sometimes called soldiers, with enlarged jaws, and these soldiers do virtually
nothing but crack the seeds for the other ants to eat. Ants of the genus Atta of
the southeastern U.S. and tropical America cultivate inside their nests a
species of fungus that is used as food by the colony. The tropical American
species are called the leaf-cutting ants, as the workers cut off pieces of
leaves, which are carried back to the nest and used to fertilize the fungus
Many ants eat a sweet fluid, called honeydew, that is excreted by aphids & scale. Some species actually keep and protect the aphids and care for their eggs. Honey pot ants of the genus Myrmecocystus of the southwestern U.S. store honeydew, utilizing certain workers as living containers for the fluid. These workers are fed enormous quantities of honeydew; their bodies become so greatly distended that they are unable to crawl about. They remain motionless in the nest, disgorging droplets of food as required.
Many ants practice trophallaxis, an association which involves complex forms of reciprocal feeding and the exchange of chemical stimulation. While feeding the larvae, the worker ants obtain from the surface of the larvae's bodies a salivary secretion that the workers eat avidly. The attraction of such metabolic products for the workers is considered to be the basis for the care of the young and for the organization and unity in the insect colony.
Colonies of ants usually establish one dwelling or nest. A few types, notably
the army and driver ants of the subfamily Dorylinae, are nomadic with nesting
phases. The nest of the doryline ants is an open mass formed by the clustered
bodies of up to a few million workers hanging from the underside of a raised log
or other surface and enclosing the queen and brood. The activities of ant
communities are characterized by a certain degree of division of labor, which in
some cases involves a permanent functional differentiation among members of the
colony. In certain harvester ants, for example, only the large-headed workers
crack seeds. More frequently, however, the division of labor is a relative
matter, as in most species of carpenter ants of the genus Campanotus. The
largest workers of these species predominate in defense, the intermediate-sized
ones in foraging, and the smallest in brood-tending, but all castes are capable
of all types of activity. In many species of campanotine and myrmecine ants,
individual workers may be temporarily specialized for foraging or brood-tending.
Like social insects in general, ants may be termed industrious, although colony activity varies from a high degree of intensity at certain times of the day (usually early morning and late afternoon, or early evening in nocturnal ants) to lethargy at other times, as through midday or in the early hours before dawn. Activity in Temperate Zone ants also varies seasonally, from a high level in midsummer to dormancy in winter. Lasting individual differences are present within the worker population of certain species; some are characteristically energetic while others are sluggish.
Some ants, especially those in the genus Formica, are capable of learning to find their way through fairly complex mazes, and they normally utilize this ability in establishing individual foraging routes from the nest. The learning capacity of ants is rigidly limited, however, and in contrast to mammalian learning is stereotyped and restricted. The complexities of ant organization that seem so remarkable to humans are actually a series of simple cues and responses .
In foraging from the nest, some ants, including the army and the driver ants, operate in definite columns following chemical trails; others vary in the individual use of cues, for example, the direction and plane of polarization of light. Many ants function only through subterranean galleries, many are strictly arboreal, but commonly the species range both above and below the surface of the earth. Communication among ants is highly efficient and is conducted mainly through tactual and chemical means, although some species exhibit vibratory and even auditory processes. Typically a "finder" ant arouses the colony, and excited nest mates may be influenced in their direction of progress from the nest by one means or another, according to species. For example, in the diminutive reddish-yellow Pharaoh ant, Monomorium pharaonis, common in kitchens, the excited finder in returning to the nest incidentally releases a track of chemical secretion that directs others to the food. Usually the excitement of the finder is greater when larger concentrations of food are discovered, and thus correspondingly greater numbers of nest mates are stimulated to forage.
The nests of many ants are inhabited by various beetles and other insects called myrmecophiles, or ant lovers, which are continuous residents; such insects range from definite parasites to somewhat beneficial types. Many ants live as temporary or permanent social parasites in the colonies of other ant species. The Amazon ant, Polyergus breviceps, carries out forays against other ants and brings back to the home nest some of the unconsumed brood to serve as slaves when they are mature. These slave ants perform the work of the Amazon colony, including excavation and brood-tending. Other slave-making ants include the sanguinary ant, F. sanguinea.
Common name for some 30,000 species of minute, usually oval-bodied arachnids of the order or subclass Acarina, or Acari ( see Arachnid ). They are worldwide in distribution. Mites resemble ticks in having the head, thorax, and abdomen fused into one unsegmented body, but they are usually much smaller. They often have three pairs of legs in the larval stage and four pairs in the nymph and adult stages. The mouth parts are adapted for piercing. Like most arachnids, mites breathe by means of tracheae (small tubes opening on the surface of the body), and they live in both aquatic and terrestrial habitats. Many are animal parasites; some, which subsist on vegetation, produce galls on plants. They are economically and medically injurious, because they carry diseases affecting livestock and humans.
Among the most important mites are the chigger and the itch mite. The follicle mites of the family Demodicidae, which infest human hair follicles and sebaceous glands, are about 0.025 cm (0.01 in) long. The bird mites of the family Dermanyssidae infest the skins of birds; the chicken mite, Dermanyssus gallinae, attacks domestic poultry and produces a form of dermatitis in humans. More than 100 species of freshwater mites in the family Hydrachnidae inhabit U.S. lakes and rivers; these animals have fringed legs that they use in swimming. Among other common mites are the so-called red spiders, or spider mites, of the genus Tetranychus, which spin spider like webs; feeding on the undersides of leaves, they destroy many types of plants.
Erinose Mite also known as Bud Rust.
They are 0,1 to 0.3 mm long. They have a greatly reduced body structure & are basically worm like with only two pairs of legs.
They inject salivary compounds into the young plant tissue, so forming the galls, often like forests of hairs, among which they live.
The mite are virtually invisible to the naked eye & their presence is indicated only by the galls they form.
Erinose mite can only infest young plant tissue.
They are spread to new areas by wind & the transport of infected plant material.